The invention relates generally to the field of photography, and in particular to liquid crystal display units for cameras.
Liquid crystal display (LCD) panels are often used in cameras to provide various mode messages or information corresponding to different operation modes of the camera.
Any one of the mode messages appearing on the LCD panel can be easily read in normal daylight ambient conditions. However, since the LCD panel does not generate light by itself, it would be difficult in low light or dark ambient conditions to read the mode messages. Thus, it is well known to back light the LCD panel using a back light source panel which is arranged at a back side of the liquid crystal display panel to illuminate the liquid crystal display panel when required. See prior art U.S. Pat. No. 5,946,507 issued Aug. 31, 1999, and U.S. Pat. No. 5,649,244 issued Jul. 15, 1997, which are incorporated in this application.
Typically, the LCD panel is referred to as being xe2x80x9ctransflectivexe2x80x9d which as is known means it is light-reflective in normal daylight ambient conditions and is light-transmissive when backlighted in low-light or dark ambient conditions.
The cross-referenced application discloses a drive circuit for an electroluminescent (EL) back light source for an LCD panel in a camera. The drive circuit connects the EL back light source to a flash capacitor in the camera which serves as a DC power source for the EL back light source.
Broadly speaking, a liquid crystal display unit for a camera comprising a liquid crystal display panel that is illuminated to facilitate viewing at least one message which can appear on the liquid crystal display panel, and a back light source panel arranged to illuminate the liquid crystal display panel, is characterized in that:
a message bearing medium is arranged to be illuminated to facilitate viewing at least one message provided on the medium in conjunction with viewing at least one message appearing on the liquid crystal display panel; and
the back light source panel has a major panel portion that illuminates the liquid crystal display panel and a minor panel portion that illuminates the message bearing medium simultaneously.
More specifically, a liquid crystal display unit for a camera comprising a liquid crystal display panel that is illuminated to facilitate viewing at least one message which can appear on the liquid crystal display panel, and a back light source panel arranged along a back side of the liquid crystal display panel to illuminate the liquid crystal display panel, is characterized in that:
the back light source panel has a panel portion that extends farther than the back side of the liquid crystal display panel to be located beyond the back side in order to provide illumination other than to the back side when the back light source panel illuminates the liquid crystal display panel;
a transparent protective cover panel covers a front side of the liquid crystal display panel to view the liquid crystal panel through the protective cover panel and has a panel portion that extends farther than the front side of the liquid crystal display panel to cover the panel portion of the back light source panel in order to permit illumination from the panel portion of the back light source panel to shine through the panel portion of the protective cover panel;
a first message bearing medium is arranged between the panel portion of the back light source panel and the panel portion of the protective cover panel to be illuminated via the panel portion of the back light source panel in order to facilitate viewing through the panel portion of the protective cover panel at least one message provided on the first message bearing medium; and
a second message bearing medium has an adhesive backing to permit the second message bearing medium to be placed on the panel portion of the protective cover panel to be illuminated via the panel portion of the back light source panel in order to facilitate viewing through the panel portion of the protective cover panel at least one message provided on the second message bearing medium.
Preferably, the second message bearing medium when placed on the panel portion of the protective cover panel covers the first message bearing medium to prevent the first message bearing medium from being viewed through the panel portion of the protective cover panel. This is necessary when at least one message provided on the second message bearing medium is in a different language than a similar message provided on the first message bearing medium.